1.\" Copyright (c) 2002 Tim J. Robbins 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd August 15, 2002 28.Dt MBRTOWC 3 29.Os 30.Sh NAME 31.Nm mbrtowc 32.Nd "convert a character to a wide-character code (restartable)" 33.Sh LIBRARY 34.Lb libc 35.Sh SYNOPSIS 36.In wchar.h 37.Ft size_t 38.Fo mbrtowc 39.Fa "wchar_t * restrict pwc" "const char * restrict s" "size_t n" 40.Fa "mbstate_t * restrict ps" 41.Fc 42.Sh DESCRIPTION 43The 44.Fn mbrtowc 45function inspects at most 46.Fa n 47bytes pointed to by 48.Fa s 49and interprets them as a multibyte character sequence 50according to the current setting of 51.Ev LC_CTYPE . 52If 53.Fa pwc 54is not 55.Dv NULL , 56the multibyte character which 57.Fa s 58represents is stored in the 59.Vt wchar_t 60it points to. 61.Pp 62If 63.Fa s 64is 65.Dv NULL , 66.Fn mbrtowc 67behaves as if 68.Fa pwc 69was 70.Dv NULL , 71.Fa s 72was an empty string 73.Pq Qq 74and 75.Fa n 76was 1. 77.Pp 78The 79.Vt mbstate_t 80argument, 81.Fa ps , 82is used to keep track of the shift state. 83If it is 84.Dv NULL , 85.Fn mbrtowc 86uses an internal, static 87.Vt mbstate_t 88object. 89.Sh RETURN VALUES 90The 91.Fn mbrtowc 92functions returns: 93.Bl -tag -width indent 94.It 0 95The first 96.Fa n 97or fewer bytes of 98.Fa s 99represent the null wide character 100.Pq Li "L'\e0'" . 101.It >0 102The first 103.Fa n 104or fewer bytes of 105.Fa s 106represent a valid character, 107.Fn mbrtowc 108returns the length (in bytes) of the multibyte sequence. 109.It Po Vt size_t Pc Ns \-2 110The first 111.Fa n 112bytes of 113.Fa s 114are an incomplete multibyte sequence. 115.It Po Vt size_t Pc Ns \-1 116The byte sequence pointed to by 117.Fa s 118is an invalid multibyte sequence. 119.El 120.Sh ERRORS 121The 122.Fn mbrtowc 123function will fail if: 124.Bl -tag -width Er 125.\".It Bq Er EINVAL 126.\"Invalid argument. 127.It Bq Er EILSEQ 128An invalid multibyte sequence was detected. 129.El 130.Sh SEE ALSO 131.Xr mbtowc 3 , 132.Xr setlocale 3 , 133.Xr wcrtomb 3 134.Sh STANDARDS 135The 136.Fn mbrtowc 137function conforms to 138.St -isoC-99 . 139.Sh BUGS 140The current implementation does not support shift states. 141